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0 votes
1 answer
53 views

Optimal Card Game Schedule

I have the responsibility of creating a schedule for a card game league. While creating the schedule, the following problem has arisen... Let $n,g,s \in \mathbb{N+}$ where $s \leq n$. Let $P = \{1, 2, ...
c.abate's user avatar
  • 213
3 votes
1 answer
410 views

How to find a set of combinations of 5 that cover all the combinations of 3 once?

I have a set of n numbers (e.g. 1 to n). For the sake of clarity, in the remaining I will use n = 10. From these 10 numbers there is $\binom{10}{3} = 120$ combinations of 3, for instance (1, 3, 5), (3,...
comlich's user avatar
  • 33
2 votes
0 answers
50 views

Enumerating separating subcollections of a set

Let $S$ be a (finite) set, and let $C \subseteq 2^S$ be a collection of subsets of $S$. We say that a subcollection $C' \subseteq C$ is separating if for any two elements of $S$ there exists a subset ...
JHF's user avatar
  • 11.2k
0 votes
1 answer
83 views

Finding sets that satisfy intersection cardinalities

Let's say I have a set of elements $V$. I can use all subsets of $V$ of size $k$ to satisfy intersection conditions. Example: $V = \{ 1, 2, 3, 4, 5\}$, $k = 3$. $|B_1 \cap B_2|=2$,$|B_2 \cap B_3|=2$,$|...
Looft's user avatar
  • 295
4 votes
1 answer
515 views

Collection of subset generating every pairs of elements

I'm looking forward to a construction with the following property: Given a set S of n elements, find a small/the smallest collection of subsets of S of size k such that for every pair of elements a, ...
Serwyn's user avatar
  • 51
5 votes
0 answers
80 views

Arranging playdate groups

At my kids' school, the kids are meeting in playdate groups of two girls and two boys every month. The groups are constructed to get as much variation in the groups over the months. Having seen too ...
Thomas Juul Eriksen's user avatar
2 votes
2 answers
688 views

Combining kindergardeners in 'fair' cookie-baking groups. Kirkman's schoolgirl problem extended version

I am coordinating cookie-baking events with kindergarten kids. This turns out to be a challenging problem, and I could use a little help: We would like a general way of creating 'fair' cookie-baking ...
user681814's user avatar
4 votes
0 answers
95 views

partitions of finite set in same-size parts having at most one element in common

Given $g \ge 2$, $k \ge 1$ and a population of $p = kg$ workers, I'm trying to figure out the longest series of work shifts such that: during each shift, all workers work in $k$ teams of g people; ...
Yann David's user avatar
2 votes
2 answers
2k views

What algorithm is a good to search a lotto design?

I'm interested what kind of algorithm would be suitable to find a lotto design? I saw that is has been proven that $L(39,7,4,7)=329$. This notation is explained in http://web.archive.org/web/...
user2219896's user avatar
5 votes
1 answer
957 views

A generalization of Kirkman's schoolgirl problem

A friend of mine asked me this question. "I have $3n$ elements, and I want to know which is the maximum number of triplets $(a,b,c)$ so that no two triplets have more than one element in common". The ...
mau's user avatar
  • 9,944